The present invention relates to a liquid crystal display device.
A liquid crystal display device having a liquid crystal layer sandwiched by two transparent substrates of glass or the like, by applying a voltage to electrodes (called pixel electrodes) formed on one of such substrates in a reticular pattern, and generating an electric force line between the pixel electrodes and an electrode (called a common electrode) formed on the same substrate or the other substrate, changes a liquid crystal molecular orientation direction, and controls a light transmittance. In general, with a liquid crystal display device called an active matrix type, by allowing and blocking conduction to the pixel electrodes by means of switching elements, such as TFT's (Thin Film Transistors), provided one on each pixel electrode, a predetermined voltage is applied between the pixel electrodes and common electrode, maintaining the liquid crystal molecular orientation direction for a certain period.
With such a liquid crystal display device, it is necessary to keep the space between the two substrates constant, for which reason a member called a spacer is inserted between the two substrates. In days gone by, transparent beads were used as the spacer, but in recent years, it has been the practice to use a photopolymer to construct on a substrate a columnar structural object called a post spacer, a photo spacer, or a columnar spacer.
However, when manufacturing a liquid crystal display device, it is possible to cut its manufacturing costs in the event that it is possible to reduce the number of manufacturing processes, and reduce the kinds of material used. For this reason, an attempt has been made to create the heretofore described post spacer without using a dedicated process and material.
A liquid crystal display device in which a post spacer is formed by stacking three kinds of material, red, blue, and green, which form color filter layers, on a black matrix is described in JP-A-2002-6132.
A liquid crystal display device in which a post spacer is formed by stacking three kinds of material, red, blue, and green, which form color filter layers is described in JP-A-2006-113204. In the invention described in JP-A-2006-113204, the height of the post spacer is controlled by making the thickness of a red color film different between a portion functioning as a pixel and a portion functioning as the post spacer.